Radiant heater



FIG. 1 is a front perspective view of a radiant heater showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a side view thereof; and,

FIG. 7 is another side view thereof.

The broken lines in the figures show portions of the radiant heater that form no part of the claimed design. 

CLAIM The ornamental design for a radiant heater, as shown and described. 